1. Field of the Invention
The present invention relates to low hygroscopic paper, more specifically, to low hygroscopic paper comprising a pulp component and/or fiber component and, a liquid crystal polymer filler component made of a liquid crystal polymer exhibiting optical anisotropy in molten state.
2. Description of the Related Art
Paper is used in a lot of applications such as electric insulation uses, prepreg substrate paper, filter materials and the like, and conventionally, pulps and fibers of aromatic polyamide, cellulose, polyolefin and the like are used.
However, when paper materials derived from aromatic polyamide and cellulose are used, since these material themselves have high hygroscopicity, the resulted paper also show high hygroscopicity, particularly, in the electric and electronic fields, hygroscopicity is required to be reduced.
On the other hand, there is disclosed a heat-resistant paper obtained by heat-pressing composite paper comprising a pulp component and/or fiber component made of cellulose, aromatic polyamide and the like and, a liquid crystal polymer filler component made of a liquid crystal polymer exhibiting optical anisotropy in molten state, at a temperature near the flow initiation temperature of the above-mentioned liquid crystal polymer (JP-A No. 9-21089).
However, this heat-resistant paper also has a problem of manifesting hygroscopicity arising from raw materials.
Under such conditions, the present inventors have intensively investigated to provide low hygroscopic paper in which hygroscopicity arising from raw materials is reduced, and resultantly, found that low hygroscopic paper having an excellently lower moisture absorption rate than expected from additivity of raw materials is unexpectedly obtained by heat-pressing composite paper which comprises a pulp component and/or fiber component and, a liquid crystal polymer filler component, at a specific temperature, leading to completion of the invention.